Trip cock interlock device



May 25, 1937. c. D. STEWART ET AL TRIP COCK INTERLOCK DEVICE 3 Sheets-Sheet 1 ww wm, b T

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TRIP COCK INTERLOCK DEVICE" Filed March 5 1936 3 SheetS-Sheel', 2

EMERGENCY P05/770W INVENTORS CARLTON D.STEWART BY ELLIS E. HEWITT ATTORNEY May 25, 1937. c. D. STEWART ET Al. 2,081,465

` TRIP COCK INTERLOCK DEVICE Filed March 5, 1956 5 Sheets-Sheet 3 CARLTON D. STEWART BY ELUS EHEWITT -ATTORNEY Patented May 25, 1937 UITED STATS PATENT OFFICE TRIP COCK INTERLOCK DEVICE Application March 5, 1936, Serial No. 67,262

15 Claims.

This invention relates to fluid pressure brakes ,for railway trains, and more particularly to a brake system having associated therewith an automatic train control means for eiecting an application of the brakes.

In fluid pressure braking equipment for railway vehicles employing means controlled from the track or otherwise and automatically operative to vent uid under pressure from the brake pipe for eiecting an application of the brakes, such as a trip cock device carried on the vehicle, it is desirable that means be provided for preventing release of the brakes until the operator performs a required act, which he lmay accomplish without leaving his post of duty.

I'he principal object of our invention is to provide means which is operative, upon a predetermined reduction in brake pipe pressure as effected by an automatically controlled means such as a trip cock device, to prevent restoration of brake pipe pressure for releasing the brakes, until manipulated by the operator.

Another object of the invention is to provide means of the type described above, which will be rendered inoperative by removal of the brake valve handle.

Another object of our invention is to provide means operative to apprise the motorman of the operation of the trip cock device.

In the accompanying drawings, Fig. 1 is a diagrammatic View, partly in section, of fluid pressure brake apparatus embodying one form of our invention; Fig. 2 is an enlarged detail plan View or" a portion of a brake valve device embodying the invention in the form shown in Fig. l; Fig. 3 is a vertical sectional view taken on the line 3--3 of Fig. 2; Fig. 4 is an enlarged detail vertical View, mainly in section, of a portion of the brake valve device embodying another form of the invention; and Fig. 5 is a sectional plan view taken on the line 5-5 of Fig. 4.

Referring to Fig. l of the drawings, the uid pressure brake apparatus illustrated is of the double end type, and comprises a brake pipe E, a supply pipe 1, a trip cock 8, a brake valve device 9 at each end of the vehicle, a main reservoir lli, a `feed valve device il, and a triple valve or controlling valve device l2 having associated therewith an auxiliary reservoir i3 and a brake cylinder 54. The controlling valve device is shown in outline Aterm, and may be of any suitable type such as a triple valve device operative upon a reduction in brake pipe pressure to supply uid under pressure from the auxiliary reservoir i3 to the brake cylinder i4, and upon an increase in brake pipe pressure to release fluid under pressure from said brake cylinder.

The brake valve device 9 may be of any one of a number of types employed in automatic brake apparatus, and as shown diagrammatically in 5 Fig. l comprises a casing having a valve chamber I6 containing a rotary slide valve I1, and may be provided with a removable handle I8 adapted to operate said rotary slide valve through the medium of a shaft I9. 10.V

The trip cock device 8 is preferably of the self resetting type and may comprise a casing having a chamber 20, which is connected with the brake pipe 6 and contains a slide valve 2|. The slide valve 2| is interposed between a pair of opposing 15 springs 23 and 24, and is adapted to control communication from the chamber 20 to the atmosphere by way of an opening 26 in the casing, the springs 23 and 24 serving to position said slide valve sol as normally to close said opening. For operating the slide valve there is provided a trip lever 21, which is pivotally mounted within the opening 26 by means of a pin 28 secured to the casing, and which operatively engages the slide valve. The trip lever 21 is arranged to be operated by engagement with a stationary track member such as that indicated at 30.

According to our invention, a pair of trip cock interlock valve devices 32 are provided, one of said devices being mounted on each of the brake 30 valve devices 9. In the form of our invention shown in Figs. 2 and 3 of the drawings, a casing is provided, comprising sections 33 and 34, which are secured together by screws 36 or other suitable means, a gasket 31 being interposed between .,5 said sections for insuring a tight joint. A bracku et 38 is provided for rigidly mounting the interlock valve device to the brake valve device 9, said bracket being clamped to the brake valve by any suitable means suchv as screws 39, and o secured to the casing of said interlock device by means of the screws 40.

A valve chamber 42 is formed in the casing section 33 and contains a valve 43, which has a fluted stem 44 extending through a suitable bore in said casing and through an .opening in the handle guard 46 of the brake valve device. A spring 49 is interposed between the valve 43 and an annular member 5l, which is screwed into a threaded interior shoulder of the casing section, said spring being adapted to urge the valve toward a seat 52 for controlling communication between the chamber 42 and the atmosphere. rI'he stem 44 is of such a length that, with the removable handle I8 operatively connected to 55 the shaft I9 and set in release or running position, the rounded end 53 of said stem operatively engages a hub Vportion 54 of said handle and maintains the valve 43 unseated. It will be apparent that,` when the handle I8 is removed from the brake valve device, the spring will be permitted to close the valve t3, thereby cutting ofi communication between the chamber 42 and the atmosphere.

A hollow valve piston 5l is slidably mounted in a suitable bore formed in the casing section 34, said valve piston being arranged to be moved by fluid pressure into sealing engagement with the portion of the gasket 3l abutting the perforate annular member 5I and surrounding the central opening therein. A coil spring 59 is interposed between the annular member 5I and the inner wall of the Valve piston for urging said piston away from the gasket and into engagement with a shoulder 66 of the casing. Formed at the fluid pressure side of the valve piston is a chamber 62, which is connected to a pipe 63 leading to the brake pipe 6, and communicates with a passage or valve chamber 64 formed in the casing and extending around the seating portion of the valve piston 5l. A valve 66 is provided in the valve chamber 64 for controlling communication between said chamber and the chamber 62, said valve having a manually operable plunger 61 extending upwardly through a bore in the cap nut 68, which has screw threaded connection with the casing section 34. The valve 66 is adapted to engage a seat 69 when the plunger is pressed downwardly against the pressure of a spring 10, which is disposed in chamber 62 between a guide portion of said valve and a plug member 'II provided for closing the lower end of the chamber, said spring acting to urge the valve away from said seat. The plunger 61 carries a collar i3 which is normally held in sealing engagement with a seat formed at the lower end of the bore in the cap nut 66 for insuring against leakage of iiuid under pressure past said plunger while the valve 66 is unseated.

As viewed in Fig. 1 of the drawings, the brake equipment is conditioned for control of the brake valve device 9 at the left-hand, which represents the brake Valve device on the front end of the vehicle and is provided with the removable handle I8. The brake valve device on the front end of the vehicle is shown in release position, the other brake valve device on the rear end of the vehicle having been set in handle off position and the handle removed.

In operation, luid under pressure flows from the main reservoir I6 to the feed valve device II, which functions in the usual manner to supply fluid at the pressure carried in the brake system through the pipe I5 to the supply pipe `I, from which fluid under pressure flows by way of a branch pipe 'I6 and a passage 'i1 in the brake valve device 9 on the front end of the vehicle to the valve chamber I6. With said brake valve device in release position, fluid under pressure flows from the chamber I6 through a port I8 in the rotary valve I'I and a passage 19 to the pipe 63 and the connected brake pipe 6.

Fluid under pressure also ows through the pipe 63 to the chamber 62 in the interlock valve device 32 at the head end of the vehicle, and in order to permit the initial charging of the brake pipe, the operator presses the plunger 6'! of said device downwardly, moving the valve 66 to the seat 69 against the pressure of the spring 10, until sufficient uid pressure has, been built up in said chamber to overcome the spring 59 and force the valve piston 5l into sealing engagement with the gasket 3l. The operator may then release the plunger, the fluid pressure in chamber 62 acting to maintain the valve piston 5l seated, thereby preventing escape of fluid under pressure from the brake pipe. It will be understood that since the handle has been removed from the brake valve device at the rear end of the vehicle, the interlock valve device on that brake valve device is automatically conditioned to prevent escape of uid under pressure from the brake pipe. The control Valve device i2 is then operative in the usual manner to charge the auxiliary reservoir I3 with fluid under pressure from the brake pipe, and to connect the brake cylinder I4 to the atmosphere.

If the trip lever 2'I of the trip valve device 8l on the Vvehicle is now brought into operative enga-gement with the stationary trip member 36, said trip lever is turned about the pivot pin 23, shifting the slide valve 2| so as to establish corn munication between the chamber 2l) and the opening 26. Fluid under pressure is then vented at an emergency rate from the brake pipe 6 by way of the connected valve chamber 26 and through the opening 26 to the atmosphere. Upon the sudden reduction in brake pipe pressure thus effected, the controlling valve device I2 is actuated in the usual well known manner to cut oi the atmospheric communication from the brake cylinder I4 and to supply uid under pressure thereto from the auxiliary reservoir I3, thereby eifecting an emergency application of the brakes.

At the same time, as the fluid pressure acting on the valve piston 5l in the trip cock interlock valve device 32 is reduced, the spring 59 is enabled to move said valve piston away from the gasket 3l, thereby establishing communication from the pipe 63 through the chamber 62, past the open valve 66, through chamber 6i, past the unseated valve piston, through chamber 52, and past the open valve i3 and its stem it to the atmosphere by way of the port 8i). The

sound produced by the iluid under pressure thus vented through the port will immediately apprise the operator that the trip cock device has been actuated, so that he may quickly take any steps desired toward controlling the vehicle, as by shutting onc the power.

After the trip cock device 8 has been operated as hereinbefore described to eiect a reduction in brake pipe pressure, the slide valve 2l in said device will be shifted by action of the spring 23 so as to close the atmospheric communication, it being understood that since the brake valve handle I8 remains in release position, fluid under pressure is supplied to the brake pipe from the main reservoir in the manner already described. With the valve piston 5l of the interlock valve device 32 unseated, however, restoration of the pressure of fluid in the brake pipe 2 to the degree necessary to effect the release of the brakes is prevented, until the operator presses down the plunger 6l to effect the operation of said interlock valve device in the manner hereinbefore described in connection with the initial charging of the system.

Referring to Figs. 4 and 5, a modiiication of our invention is illustrated diagrammatically, in which the trip cock interlock valve device B is provided, comprising a casing 35 and a cover plate 86 secured thereto by means of screws Si?, a gasket 88 being interposed between the casing and cover plate. The casing is carried on a gli) bracket member 90, tov which it is secured by means of the screws 9i, and the bracket member is rigidly mounted on the brake valve device 9 by any suitable means, such as the bolts 92.

. Formed within the casing 85 is a bushing portion 94 having a bore in which is slidably mounted a valve piston 95, said valve piston forming at one side a chamber 97, which is connected to the pipe 53 and consequently with the brake pipe. The valve piston 95 is adapted to be moved into sealing engagement with, the gasket 88, said valve piston being normally urged away from said gasket by the pressure of a spring 98, which acts against an interior shoulder 99 of said valve piston. A plurality of passages II are formed between said casing 85 and the bushing portion 9d for providing communication from the chamber 9i around said bushing portion to an opening therein, which opening is adapted to be closed by the Valve piston 95 when in sealing engagement with the gasket 88 and opened when said valve piston is moved toward the stop shoulder IGS provided on the end of the bushing portion.

Fer controlling the operation of the valve piston 95, a cam linkage mechanism is provided, comprising a link member |94, one end of which `passes through a central opening in the end plate 88 and gasket 88 and is pivotally connected to the interior bosses |95 of the valve piston 95 by means of a transversely disposed pin I06. The other end of the link member I94 is piloted through a suitable opening in the handle guard 95 and is provided with a substantially ringshaped portion IGI, which is adapted to surround the shaft i9 of the brake valve device 9 below the hub portion of the removable handle i8, said ring-shaped portion being slidably guided between the arms IUS of the bracket member 92. Secured to the shaft I9 within the ringshaped portion Ili'I is a cam |59, which is arranged to engage an inwardly projecting surface IIS of said ring-shaped portion when the handle it is placed in handle o position, or in service or emergency position as shown in the drawings, the link member 99 being thereby positioned so as to maintain the valvepiston 95 in engagement with the gasket 83. Anv operating member III is secured to the link member IM 1- by any suitable means, such as by welding, for

permitting manual operation of said link member and the connected valve piston.

. The operation of the interlock valve device 84 is similar to that oi the interlock valve device 32 hereinbefore described. With the handle I8 of the brake valve device 9 at the front end of the vehicle placed in release position, uid at the pressure maintained in the brake pipe in the usual manner is supplied throught the pipe 83 to the chamber 9?. Since the cam E99 is not in engagement with the surface II!) of the ringshaped portion Il in this position of the brake valve device, the operator moves the operating member iii and link member Illllto the right, and thereby holds the valve piston 95 in sealing engagement with the gasket 88 until the fluid pressure in chamber S'I has built up suiiiciently to overcome the pressure o the spring 98 and to maintain said valve piston closed, The brake valve device at the rear end of the vehicle is, of course, put in the handle ofi position, the interlock valve device iii thereon` being held in the closed position by engagement of the cam 99 with the ring-shaped portion IGI as shown in Figs. 4 and 5` of the drawings.

If the trip cock device is operated to vent uid under pressure from the brake pipe in the manner hereinbefore described, the consequent reduction in the pressure of uid in the chamber 9'I'of the interlock valve device 84 to the predetermined degree will permit the spring 98 to shift the valve piston 95 away from the gasket 88 so as to establish communication between passages IUI and a central opening in the end plate 86, permitting fluid under pressure to ow from the brake pipe by Way of the pipe 63, the chamber 91, through the passages ISI, past the unseated valve piston and through said opening to the atmosphere.

It will thus be seen that our invention provides trip cock interlock means arranged to permit the usual service control of the brakes through the medium of the engineers brake valve device, and which is rendered operative upon a predetermined reduction in brake pipe pressure effected by automatic means, to prevent restoration of the normal brake pipe pressure for releasing the brakes, until the operator performs a required act.

While two illustrative embodiments of our invention have been described in detail, it is not our intention to limit its scope to those embodiments or otherwise than by the terms of the appended claims.

Having now described our invention, what we claim as new and desire to secure by Letters Patent, is:

1. In a railway vehicle brake system, the combination with a brake pipe, a reduction in pressure in which is adapted to eiect an application of the brakes, and means controlled from the track for venting fluid under pressure from said brake pipe, of valve means operative to an open position upon a predetermined reduction in brake pipe pressure for venting uid under pressure from the brake pipe, and means adapted to be manually operated for effecting the return of said valve means to the normal closed position.

2. In a railway vehicle brake system, the combination with a brake pipe, a reduction in pressure in which is adapted to effect an application of the brakes, and means controlled from the track for venting iluid under pressure from said brake pipe, of valve means normally maintained in closed position by the pressure of uid in the brake pipe and operative to open position upon a predetermined reduction in brake pipe pressure for venting uid under pressure from said brake pipe, and means adapted to be manually operated for effecting the return of said valve means to normal position.

3. In a fluid pressure brake, in combination, a brake pipe, means for' supplying fluid under pressure to said brake pipe, brake controlling mechanism operative upon a reduction in the pressure of fluid in said brake pipe to elect an application of the brakes and upon an increase in brake pipe pressure to eiect the release of the brakes, means automatically operative to vent uid under pressure from said brake pipe, interlock means constantly subject to brake pipe pressure and operative to a position upon a predetermined reduction in brake pipe pressure to prevent a subsequent increase in said brake pipe pressure and thereby the release of the brakes, and yielding means for operating said interlock means to anotherA position in response to manual control for permitting an increase in brake pipe pressure.

4. In a fluid pressure brake, in combination, a brake pipe, means for supplying fluid under pressure to said brake pipe, brake controlling mechanism operative upon a reduction in the pressure of fluid in said brake pipe to effect an application of the brakes and upon an increase in brake pipe pressure to effect the release of the brakes, means automatically operative to vent fluid under pressure from said brake pipe, valve means always subject to brake pipe pressure and operative upon a predetermined reduction in brake pipe pressure for establishing communication from the brake pipe to atmosphere, and yielding means operative manually for effecting the operation of said valve means for closing said communication.

5. In a fluid pressure brake, in combination, a brake pipe, means for supplying fluid under pressure to said brake pipe, brake controlling mechanism operative upon a reduction in the pressure of fluid in said brake pipe to effect an application of the brakes and upon an increase in brake pipe pressure to effect the release of the brakes, means automatically operative to Vent fluid under pressure from said brake pipe, a spring, and valve means constantly subject to the opposing pressures of fluid in the brake pipe and said spring and operative upon a predetermined reduction .in brake pipe pressure to establish communication between the brake pipe and the atmosphere, and manually operable Vyielding means for effecting the actuation of said valve means to cut of said communication. l

6. In a vehicle brake apparatus, the combination with a brake pipe, means for supplying fluid under pressure to said brake pipe, 'and brake controlling mechanism operative upon a reduction in the pressure in said brake pipe to effect an application of the brakes and upon an increase in brake pipe pressure to effect the release of the brakes, of automatically controlled means operative to open communicationV from the brake pipe to the atmosphere and then to cut oif said communication, valve means constantly subject to brake pipe pressure and operative to a position, in response to operation of said automatically controlled means, to prevent restoration of brake pipe pressure, and yielding- 1y biased means manually operative to effect movement of said valve means to a normal position for permitting build up in brake pipe pressure.

7. In a vehicle brake apparatus, the combination with a brake pipe, means for supplying fluid under pressure to said brake pipe, and brake controlling mechanism operative upon a reduction in the pressure in said brake pipe to effect an application of the brakes and upon an increase in brake pipe pressure to effect the release of the brakes, of automatically controlled means operative to open communication from the brake pipe to the atmosphere and then to cut off said communication, yielding means, and valve means operative by said yielding means in response to operation of said automatically controlled means to establish and maintain communication from the brake pipe to atmosphere to prevent restoration of brake pipe pressure for releasing the brakes, said valve means' being manually operable against said yielding means to close said atmospheric communication.

8. In a fluid pressure brake apparatus, in combination, a brake pipe, means for supplying fluid under pressure to said brake pipe, brake controlling valve means operative upon a reduction in the pressure of fluid in said brake pipe to effect an application of the brakes and upon an increase in brake pipe pressure to effect the release of the brakes, automatically controlled means operative to vent fluid under pressure from said brake pipe, and an interlock valve device comprising valve means always subject to brake pipe pressure and responsive tothe reduction in brake pipe pressure to move to a position for preventing restoration of brake pipe pressure, manually operable yielding means for effecting operation of said valve means out of said position to permit the release of' the brakes, and means for indicating to the operator that said valve means has moved to said position.

9. In a fluid pressure brake for a railway vehicle, in combination, a brake pipe, a reduction of fluid pressure in which is adapted to effect an application of the brakes and an increase of fluid pressure in which is adapted to effect the release of the brakes, means controlled from the track for venting uid under pressure from the brake pipe, valve means operative upon a predetermined reduction of brake pipe pressure to continue the venting of fluid under pressure from the brake pipe, means operated manually to effect the operation of said Valve means to cut off said venting, and means for rendering the valve means ineffective to vent brake pipe fluid.

10. In a fluid pressure brake, in combination, a brake pipe, a brake valve device for controlling the supply of fluid under pressure to the brake pipe, brake controlling valve means operative upon a reduction in the pressure of fluid in said brake pipe to effect an application of the brakes and upon an increase in brake pipe pressure to effect the release of the brakes, means manually controlled independently of said brake valve device and operative upon a predetermined reduction in brake pipe pressure to establish communication from the brake pipe to atmosphere, until manipulated to close said communication for permitting the release of the brakes, and means conditioned by said brake valve device for rendering said manually controlled means ineffective to vent fluid under pressure from the brake pipe.

11, In a fluid pressure brake, the combination with a brake pipe, a reduction in pressure in which is adapted to effect an application of the brakes and an increase in pressure in which is adapted to eifectat'he release of the brakes, of automatically controlled means operative from the track to vent fluid under pressure from said brake pipe, and a valve device responsive to a reduction in brake pipe pressure comprising a spring, a valve piston subject to the opposing pressures of said brake pipe and said spring for controlling communication from said brake pipe to the atmosphere, and manually controlled means adapted to effect the operation of said valve piston against the pressure of said spring to close said communication for permitting suicient build up of brake pipe pressure to maintain said valve piston closed.

12. In a uid pressure brake, the combination with a ,brake pipe, a reduction in pressure in which is adapted to effect an application of the brakes and an increase in pressure in which is adapted to effect the release of the brakes, of automatically controlled means operative to vent fiuid under pressure from said brake pipe, and a valve device responsive to a reduction in brake pipe pressure comprising a casing having a passage communicating vvith the brake pipe, a spring, a valve piston subject to the opposing pressures of the brake pipe and said spring for controlling communication from said passage and consequently from the brake pipe to the atmosphere, and a normally open valve adapted to be manually operated to close said passage for permitting the pressure of fluid in said brake pipe to force said valve piston to its seat.

13. In a fluid pressure brake for a railway vehicle, in combination, a brake pipe, a brake valve device having a release position for supplying fluid under pressure to said brake pipe and a handle off position, brake controlling mechanism operative upon a reduction in the pressure of fluid in said brake pipe to effect an application of the brakes and upon an increase in brake pipe pressure to effect the release of the brakes, means controlled from the track and automatically operative to vent fluid under pressure from the brake pipe, valve means adapted to be set in a normal position to permit charging of the brake pipe with uid under pressure by said brake valve device in the release position thereof and operative from said normal position upon a predetermined reduction in brake pipe pressure for preventing a subsequent restoration of brake pipe pressure until reset, means adapted to be manually operated for effecting the setting of said valve means, and means controlled by said brake valve device in the handle off position for rendering said valve means ineffective to preventy build up in brake pipe pressure.

14. In a fluid pressure brake for railway vehicles, the combination with a brake pipe, a reduction in pressure in which is adapted to effect an application of the brakes and an increase in pressure in which is adapted to effect the release of the brakes,and a brake Valve device having release, lap, service and emergency positions, of automatic means controlled from the track for venting fluid under pressure from the brake pipe, valve means operative upon a predetermined reduction in brake pipe pressure for establishing communication from the brake pipe to the atmosphere, means manually operative to effect movement of said valve means to close said communication, and means controlled by said brake valve device and arranged to render said valve means ineffective in all positions of said brake valve device except release position.

15. In a uid pressure brake, the combination with a brake pipe, a reduction in pressure in which is adapted to effect an application of the brakes and an increase in pressure in which is adapted to effect the release of the brakes, of automatically controlled means operative to vent fluid under pressure from said brake pipe, and a valve device responsive to a reduction in brake pipe pressure comprising a casing having a passage communicating with the brake pipe, a spring, a valve piston subject to the opposing pressures of the brake pipe and said spring for controlling communication from said passage and consequently from the brake pipe to the atmosphere, an auxiliary valve manually operable to a seated position to close said passage for permitting the pressure in said brake pipe to force said valve piston to its seat, and yielding means for biasing said auxiliary valve toward an unseated position.

'CARLTON D. STEWART. ELLIS E. HEWITT. 

